LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2000 >> RAV4 Base, AWD, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 7 (Engine Control System Self-Diagnostics - V6) >> Diagnostic Tests >> DTC P1520: Stoplight Switch Signal Circuit (A/T Only) >> Diagnosis & Repair
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnosis & Repair

WARNING: This page is about a different car, the 2000 Toyota Tundra. However, it is still accessible from the selected car via links, so may be relevant.
  1. Check stoplight operation. If stoplights do not operate properly, repair as necessary and retest system. See EXTERIOR LIGHTS article in ACCESSORIES & EQUIPMENT. If stoplights operate properly, go to next step.
  2. Access ECM behind glove box. Turn ignition on. Using DVOM, backprobe ECM harness connector. On models with California emissions, measure voltage between ground and terminal No. 15 (Green/White wire) at ECM harness connector E3. See Figure. On models without California emissions, measure voltage between ground and terminal No. 24 (Green/White wire) at ECM harness connector E3. See Figure. On all models, voltage should be 7.5-14.0 volts with brake pedal depressed, and less than 1.5 volts with brake pedal released. If voltage is not as specified, go to next step. If voltage is as specified, problem is intermittent. Check component and ECM connections.
  3. Check for an open or short in wiring between ECM and stoplight switch. If problem exists, repair wiring as necessary. If problem does not exist, replace ECM.
scientia non olet · About LEMON Manuals